Loses DNS connection after scan

Yesterday, during the night, I left ESS running an AV scan. When I returned in the morning. The scan completed but I couldn't enter any website. I had a P2P program running and it was still running fine (doesn't use DNS to connect to peers).

Today (just now), the scan didn't complete. It just stopped at about 62% and I lost DNS again.

This just occurs when I make a scan.

Can't make DNS request at all and it seems very random. If I disable filtering they go through.